Alert archive / Minnesota / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 78, NWS Duluth, MN

August 1, 2002Carlton County, Lake County, Minnesota; Bayfield County, Douglas County, Wisconsin

NWS Duluth, MN issued this severe thunderstorm warning at Aug 1, 2002, 2:17 AM CDT for Carlton County, Lake County, Minnesota; Bayfield County, Douglas County, Wisconsin. It was in force for 73 min. 5 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Aug 1, 2002, 2:17 AM CDT (07:17 UTC)
Expired: Aug 1, 2002, 3:30 AM CDT
In force: 73 min
Issued by: NWS Duluth, MN
Area: Counties, with a storm outline in the text

Counties Carlton County, MN, Lake County, MN, Bayfield County, WI, Douglas County, WI

The radar

The Duluth radar (KDLH), 18 km from the middle of the area, began a volume at 07:18 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

Time	Report	Where
Aug 1, 2:53 AM CDT	Hail 0.88	Hermantown, MN
Aug 1, 2:55 AM CDT	Hail 1.75	Duluth, MN
Aug 1, 2:59 AM CDT	Hail 1	New Duluth, MN
Aug 1, 3:07 AM CDT	Hail 0.88	Superior, WI
Aug 1, 3:09 AM CDT	Hail 0.88	Duluth, MN

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Jul 31, 10:00 PM CDT	Severe Thunderstorm Watch	SPC	6 hr

The nearest sounding before it

International Fa, MN (KINL), launched 00:00Z, 7.3 hours before the alert went out and 218 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 1707 J/kg
Mixed-layer CIN: -48 J/kg
Mixed-layer LCL: 1366 m above ground
0-6 km bulk shear: 50 kt
0-1 km storm-relative helicity: 20 m²/s²
0-3 km storm-relative helicity: 88 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 1.1

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

218 
WUUS53 KDLH 010717
SVRDLH
MNC017-075-WIC007-031-010830-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE DULUTH MN
217 AM CDT THU AUG 1 2002

THE NATIONAL WEATHER SERVICE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CARLTON COUNTY IN NORTHEAST MINNESOTA...
  DOUGLAS COUNTY IN NORTHWEST WISCONSIN...
  BAYFIELD COUNTY IN NORTHWEST WISCONSIN...
  LAKE COUNTY IN NORTHEAST MINNESOTA...

* UNTIL 330 AM CDT.

* AT 217 AM DOPPLER RADAR INDICATED A LINE OF SEVERE THUNDERSTORMS
  EXTENDING FROM 24 MILES NORTH OF DULUTH TO 28 MILES WEST OF
  DULUTH...MOVING SOUTHEAST AT 45 MPH.

* THE LINE OF SEVERE THUNDERSTORMS WILL BE NEAR...
  DULUTH AROUND 225 AM...
  CLOQUET AROUND 230 AM...
  SUPERIOR AROUND 230 AM...
  TWO HARBORS AROUND 245 AM...
  PORT WING AND MAPLE AROUND 300 AM...

DAMAGING HAIL UP TO ONE INCH AND DESTRUCTIVE WINDS OVER 60 MPH ARE
LIKELY WITH THESE STORMS. TAKE COVER IN A STURDY BUILDING AND STAY
AWAY FROM WINDOWS.

.END

LAT...LON 4716 9211 4670 9281 4659 9247 4638 9159
          4694 9076

SHIMON

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Duluth, MN wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 1, 2:00 AM CDT, 17 minutes earlier.

Area forecast discussion, Aug 1, 2:00 AM CDT, 17 minutes before

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE DULUTH MN
200 AM CDT THU AUG 01 2002

CURRENTLY STRONG TO SEVERE THUNDERSTORMS MOVING THROUGH THE AREA.
STRONG MID-LEVEL JET COUPLED WITH UNSTABLE AIR MASS AND SFC FRONT
ARE THE INGREDIENTS CURRENTLY.  STORMS ARE SHOWING ELEVATED
CHARACTERISTICS AT THE MOMENT.  HEAVY RAINS (FLOODING) AND HAIL
APPEAR TO BE THE SEVERE THREAT.  SPC MESO ANALYSIS INDICATES LCL
HEIGHTS OF 800 M AND LOWERING WITH TIME SO SEVERE WINDS ARE STILL A
POSSIBLE THREAT.

WITH MORE TSRA FIRING OVER EASTERN ND... DOES NOT APPEAR CONVECTION
WILL EXIT THE EASTERN ZONES OF FORECAST AREA UNTIL 18Z.  WILL
MAINTAIN PRECIP MENTION UNTIL NOON FOR MUCH OF FORECAST AREA.  WILL
LOOK AT RADAR, SATELLITE, ETC., JUST BEFORE ISSUANCE TO DEFINE THE
AREA.

DOES CLEAR OUT FAIRLY WELL AS COOL HIGH PRESSURE BEGINS TO BUILD IN
BEHIND THE CURRENT SYSTEM.  SOME SC IS EXPECTED TO LINGER BEHIND THE
FRONT THIS AFTERNOON, BUT SHOULD BE THIN. BREEZY NORTHWEST WINDS
WILL PRODUCE MIXING PREVENTING TONIGHT FROM BEING TOO CHILLY.

FRIDAY WILL BE SUNNY WITH CU FORMING IN THE AFTERNOON.  OTHERWISE A
RELATIVELY COOL DAY WITH WINDS CALMING (HIGH PRESSURE OVERHEAD
DURING THE AFTERNOON).  FRIDAY NIGHT WILL BE THE CHILLY NIGHT, WEAK
RETURN FLOW WILL START BUT MAINLY ALOFT.  GOOD RADIATION COOLING
WITH CALM SFC WINDS FRIDAY NIGHT.

.DLH...SVR WATCH 561 FOR MUCH OF NORTHEAST MINNESOTA ALONG WITH
DOUGLAS COUNTY IN WISCONSIN THROUGH 09Z.

KFM

The office that day

Everything else NWS Duluth, MN issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 31, 11:47 PM CDT	Severe Thunderstorm Warning	DLH	Cass, Itasca	58 min
Aug 1, 12:50 AM CDT	Severe Thunderstorm Warning	DLH	Cass, Itasca, Saint Louis	70 min
Aug 1, 1:00 AM CDT	Flash Flood Warning	DLH	Aitkin, Cass, Itasca	3 hr
Aug 1, 1:08 AM CDT	Flash Flood Warning	DLH	Aitkin, Cass, Itasca	3 hr
Aug 1, 1:53 AM CDT	Severe Thunderstorm Warning	DLH	Saint Louis	52 min
Aug 1, 2:48 AM CDT	Severe Thunderstorm Warning	DLH	Saint Louis	27 min
Aug 1, 3:08 AM CDT	Special Marine Warning	DLH		2 hr
Aug 1, 3:56 AM CDT	Special Marine Warning	DLH		49 min
Aug 1, 3:56 AM CDT	Special Marine Warning	DLH		49 min
Aug 1, 3:56 AM CDT	Special Marine Warning	DLH		49 min
Aug 1, 3:56 AM CDT	Special Marine Warning	DLH		49 min
Aug 1, 3:32 AM CDT	Severe Thunderstorm Warning	DLH	Ashland, Bayfield, Douglas	73 min
Aug 1, 4:00 AM CDT	Severe Thunderstorm Warning	DLH	Iron	60 min
Aug 1, 8:01 AM CDT	Severe Thunderstorm Warning	DLH	Price	59 min

Nearby

Severe Thunderstorm Warnings in Minnesota, 2002 Severe Thunderstorm Warnings in Wisconsin, 2002 Every severe thunderstorm warning in 2002

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.